CVE-2026-8981 - Before 4 Plugin
CVE-2026-8981
The Custom Block Builder WordPress plugin before 4.3.0 does not consistently check the unfiltered_html capability across all paths that write to its block template code fields, allowing administrators on multisite installations (or single-site installs with DISALLOW_UNFILTERED_HTML defined) to inject arbitrary JavaScript that executes for any visitor of pages embedding the affected block.
CVE-2026-8981
LOW
CVSS 3.5
Published 2026-06-09
Updated 2026-06-09
AI Risk Low (30/100)
Active Exploit: No strong signal
Published Exploit: No public exploit references
Priority: P5 Monitor
Severity Band
LOW
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N
Affected Components
2
Reference Links
1
AI Risk Engine
Low (30/100)
Exploitability
Low
Active Exploitation
No strong signal
Published Exploit Status
No public exploit references
AI Context
Machine-generated threat intelligence
AI
Updated 4 hours ago
AI enriched 4 hours ago (2026-06-09 21:25 UTC)
Technical Summary
The Custom Block Builder WordPress plugin before 4.3.0 does not consistently check the unfiltered_html capability across all paths that write to its block template code fields, allowing administrators on multisite installations (or single-site installs with DISALLOW_UNFILTERED_HTML defined) to inject arbitrary JavaScript that executes for any visitor of pages embedding the affected block.
Potential Impact
Severity is LOW (CVSS 3.5). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.
Exploitability Assessment
Exploitability is assessed as Low based on severity and technical exposure profile.
Primary risk drivers: severity and technical exposure profile
Mitigation Recommendations
Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.
Detection & Monitoring
Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.
Business Impact Lens
AI risk score 30/100 (Low, Low) with priority P5 Monitor. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.